Connecting Portable Solar Generator to Inside Electrical

[Rpatrick16]

Recently bought my 2nd Solar Portable Generator; it has a 1600 watt capacity. Playing around with it I plugged it into the outside "shore power plug" and discovered I could use many the microwave, and other ac electrical outlets in the trailer. This was a great discovery due to the fact when doing quick boon docking overnight stops I no longer needed to use my gas-powered generator.
I used a 120v adaptor on the 50 amp outside plug to hook-up the portable solar generator. It worked so well that now I want to create an "inside the trailer" plug to make this connection directly into the trailers electrical system.
Has anyone done this?
How do I do this?
We have a 25' RT 2020 International

Thanks
Pat

[OutdoorIdaho]

Am I understanding correctly that you would like to duplicate the exterior AC plug on the interior of the trailer? Curious what you mean by 'directly into the trailers electrical system.'

[richard5933]

It's not as simply as just installing a second input, as having two inputs allows the possibility that both could be used at the same time creating a dangerous situation.

A transfer switch is required so that only one of the input locations is connected to the trailer's 120vac system at a time.

Some Airstream trailers are equipped with a second 120vac input, designed to make connected a generator more convenient. On these trailers there is a transfer switch which will automatically connect the input with power. You could install one of these automatic transfer switches, but it's likely overkill. There are also manual transfer switches, but again the installation of the switch might make the project more work than it's worth.

For the trouble and expense of installing a transfer switch and a second 120vac input you could likely install an inverter which would run from the trailer's battery bank.

If your trailer already has the second outside 120vac input, I suppose it would be possible to re-route the wiring to the second input and use that to create your inside 120vac input. Not sure if it would be worth it either.

[DavePDX]

This thread is interesting to me, as I've followed a similar path, and would also ideally like to add an interior Shore Power outlet.

Our Interstate 19 came with 200amps of lithium and 1000 watt inverter. The A/C and microwave require shore power or the generator to be on, and these are not always options, so I bought a EcoFlow Delta Pro Max 2000 (2016Wh), similar to the OP. To my delight, when I connect that to the shore power input with the adapter, the AC and microwave work fine. The EcoFlow has a wonderful display and iPhone app, which gives a lot of info about the power going in and out, and it showed a significant draw (450 watts) even when nothing is turned on. I initially (wrongly) attributed that to the Inverter, but now believe is mostly the Converter. In other words, a lot of juice was going into the House batteries. I discovered that if I turn off the circuit breaker for the converter/inverter, my draw drops to 75 watts. With that circuit turned off, the Inverter does not come on automatically, but I can still turn it on as needed from the panel, and it does not significantly increase the draw.

I feel this is great progress, and nearly all I need, as it almost doubles our house power, and the EcoFlow can be recharged very quickly (~1 hr) when shore power is available and also used for other purposes outside the van.

Getting back to OP's specific question, I agree with richard5933 that a transfer switch is almost certainly needed to add an interior connection. If possible, I'd suggest it would also be ideal to have the converter/inverter circuit automatically turned off, when switched to this new Interior power. Perhaps a transfer switch could be wired to isolate the new battery pack from the converter to prevent that from being an issue? I'm checking into this with AM Solar, who I believe are well qualified to provide some answers and do the work. I'll post more to the thread if I'm able to get more info. Meanwhile, I'd love to hear input from others who have more experience or knowledge!

[richard5933]

A very simplistic solution to this is just to plug things directly into the power pack when used inside your trailer. Other than a handful of devices we don't use much on 120v power that can run from one of those.

They can't run the a/c or a space heater, so mostly it will be to power a television, to charge a computer, or maybe to run the microwave. A good power strip might allow those to be used directly from the power pack.

[DavePDX]

Actually my unit can easily run the AC, microwave, electric kettle, or heater, and that’s my primary reason for getting it in the first place. The 1000 watt inverter in our Interstate is pretty useless for our needs since it won’t run any of those things. My personal goals are to: extend our boondocking capability and to enable us to use those appliances without running the generator. Plugging it into the shore input gets us there, but is a bit inconvenient and awkward, hence the desire for the op’s request.

[richard5933]

Originally Posted by DavePDX

Actually my unit can easily run the AC, microwave, electric kettle, or heater, and that’s my primary reason for getting it in the first place. The 1000 watt inverter in our Interstate is pretty useless for our needs since it won’t run any of those things. My personal goals are to: extend our boondocking capability and to enable us to use those appliances without running the generator. Plugging it into the shore input gets us there, but is a bit inconvenient and awkward, hence the desire for the op’s request.

In this case, the only good option that I see is to go the transfer switch route. That will allow all the trailer's 120v circuits to run from the power pack without having to run a cord outside.

That said, the OP is talking about a 1600-w unit. How long will that run the average a/c unit? Maybe 30-45 minutes? Not sure if that would make a transfer switch install worthwhile.

That 1,000-w inverter could be upgraded easier than installing a transfer switch and second 120v input in many situations, depending on the setup.

[DavePDX]

Originally Posted by richard5933

In this case, the only good option that I see is to go the transfer switch route. That will allow all the trailer's 120v circuits to run from the power pack without having to run a cord outside.

That said, the OP is talking about a 1600-w unit. How long will that run the average a/c unit? Maybe 30-45 minutes? Not sure if that would make a transfer switch install worthwhile.

That 1,000-w inverter could be upgraded easier than installing a transfer switch and second 120v input in many situations, depending on the setup.

Yes, the OP's battery pack is smaller than mine, but still could provide a nice cushion. I can get about 3.5 - 4 hours of AC with mine, so I would think he'd get closer to 2 hrs of use. In my case, I rarely run the AC for very long. Primarily, I want to be able to use the microwave, electric kettle and other small appliances without running the generator.

My first thought was upgrading my inverter, but that actually was a more expensive and difficult proposition, and wouldn't have given me any extra longevity. The OP's situation may be different.

[zeekwad]

Originally Posted by richard5933

In this case, the only good option that I see is to go the transfer switch route. That will allow all the trailer's 120v circuits to run from the power pack without having to run a cord outside.

That said, the OP is talking about a 1600-w unit. How long will that run the average a/c unit? Maybe 30-45 minutes? Not sure if that would make a transfer switch install worthwhile.

That 1,000-w inverter could be upgraded easier than installing a transfer switch and second 120v input in many situations, depending on the setup.

Your math is about right. I have a Ecoflow Delta Pro (3600-w) and it'll run the A/C in my Interstate for about 2 hours. If the transfer switch was an easy enough add, I'd probably do it. If only from keeping the expensive Delta Pro out of the elements. That said, it's also easy enough to stick the Delta Pro in the back of the van and run the 30A cord to the usual place.

I think the main benefit of these gizmos is not in running the A/C, but for us, it's being able to easily use the non-inverter 120v outlets in the kitchen galley (waffle maker, etc) and give us an extra day or two boondocking without having to run a "dirty" generator.

[richard5933]

What about just running a very short shore power cord up through the floor of the trailer and into a cabinet just inside of the nose of the trailer. On my trailer there is a small area in front of the spare tire which is fairly well protected from the elements, and if you have a cabinet above that area you could hide the cord in there until needed to plug in the power unit. There are plastic pass throughs made for this like this one: https://www.amazon.com/RecPro-Traile...02435475&psc=1

Might not work in every trailer, but if it can be done then you can have the power unit inside out of the weather and still plugged in to the outside power inlet.

Just trying to come up with alternatives to rewiring the 120v feed to install a transfer switch.

[Rpatrick16]

For starters, thanks to all who have responded to my question. Let me try and clarify my purpose.
I'm not concerned about running the AC on my Portable Power Unit. The trailer has two units. My current portable unit might run one for an hour or so but that's not my desire.
The trailer has a 2000 watt inverter. However, it only has a couple of AC outlets that take advantage of the inverter such as the TV's, the entertainment system in the overhead cabinet. There are no inverter outlets in the galley, nor the cabinet between the twin beds. The microwave will not operate on "inverted power".
With the portable power station connected to the 50 amp shore power plug via an adaptor I can operate basically everything. I can use the toaster, coffee maker, microwave, TV's etc.
Since the plug for the microwave is not accessible I can't make a direct connection to the portable power unit.
I am aware that I could "backfeed" the power coming from the portable unit thru any interior ac outlet but I know this is very dangerous and probably illegal.
All of the electrical, fuse panel etc is accessible under the dinette seating area in the front of the trailer. My trailer is a "rear bed" unit.
Where could I find a set of instructions to install a transfer switch?
Currently, I am running a 12' heavy duty extension under the couch into an outside storage compartment and into the external shore power plug. The downer of this setup is the storage compartment door can't be closed. Also, I'm probably experiencing "bleed off" by the length of the extension cord.
Thanks again for everyones input.

[richard5933]

Originally Posted by Rpatrick16

...Where could I find a set of instructions to install a transfer switch?....

The process itself is pretty straightforward...instructions will likely come with the transfer switch itself. here's a brief summary.

1) The current cable connecting the existing exterior shore power inlet is re-routed to one of the input sides of the transfer switch. It used to go to feed the 120v breaker panel - now it will feed one of the inputs on the transfer switch.

2) The new interior shore power inlet is installed and connected to the second input side of the transfer switch.

3) A new cable is run from the output of the transfer switch to the point on the 120v breaker panel which used to be fed from the exterior shore power inlet.

4) The cable used to make the connections needs to be of the proper size, and assuming that the current setup is wired correctly it would be the same size wire as is currently used to connect the shore power inlet to the breaker panel.

5) Make sure that all ground connections are made.

6) Torque all connections to the specified torque. Loose connections in transfer switches are a common cause of failure/fires.

The process itself is not complicated - you're essentially installing a big switch box which has two inputs and one output. The difficult part is physically running the cables between everything. On some trailers this is easy, and on others it takes a large shoe horn to get everything to fit. The cables used to make the connection are rather fat and difficult to work with, especially in tight spaces. If you position the transfer switch well, you will be able to re-use the existing wiring that connects the existing shore power inlet to the breaker panel to feed the transfer switch on one side.